Does Jesus demand we obey the Ten Commandments (Matthew 5:13-20)? The word commandments does not mean the Ten Commandments. That makes the Bible say what it does not say. The phrase law and the prophets means the entire Old Testament with over 600 commandments. Deuteronomy expands the ten via many more commandments. No Christian keeps the Ten Commandments as the law teaches, not even those who practice the original Sabbath day. If they did, they would put to death idolaters, Sabbath breakers, adulterers and those who dishonor their parents. That’s what the law demands to keep the Ten Commandments in the letter. Jesus explained how Christians keep the spirit of the law in the Sermon on the Mount. Christians fulfill the law in spirit not the letter. The letter kills, but the spirit gives life (2 Corinthians 3:6).
Deuteronomy expounds the Ten Commandments (#1 6-11; #2 12; #3 13:1-14:21; #4 14:22-16:17; #5 16:18-18:22; #6 19-21; #7 22:1-23:14; #8 23:15-24:7; #9 24:8-16; #10 24:17-26:15).* No Christian keeps the letter of the law, not as Deuteronomy demands. How do Christians keep the law if not in the letter? Some claim to keep it in the letter and the spirit, but the letter kills (2 Corinthians 3:6). The only option left is keeping the law in spirit. Three commandments teach us how. Circumcision is no longer required in the flesh in the New Testament, but in the heart (Romans 2:29); there remains a Sabbath rest in Jesus for eternity (Matthew 11:28; Hebrews 4) and love fulfills the whole law (Romans 13:8-10; Galatians 5:14).
*Hill, Andrew E. & Walton, John H. A Survey of the Old Testament. Zondervan Publishing House. 1991. 58.